A software stack comprises a set of software subsystems or components that can perform a task without further external dependencies. One example of a software stack is a file system. Computer systems use file systems to store and organize data on storage devices such as hard disks. File systems can be implemented as an index or a database containing a physical location of every piece of data on one or more storage devices. In Unix™ based computer systems, a file system is first “mounted” in order to enable software applications to access directories and files on one or more storage device managed by the file system.
In networked computing environments, file systems can be implemented in Storage Area Networks (SANs) and Network Attached Storage (NAS) systems. In both SAN and NAS systems, data is stored in “blocks” on a storage device managed by a storage controller (also known as a server), wherein a block is a sequence of bytes having a specific length (e.g., one megabyte). In a SAN configuration, a file system is mounted on a host computer in communication with the storage controller via the SAN, and the storage controller processes block-level storage commands (e.g., read data from a specific block, and write data to a specific block) received from the host computer.
In a NAS system, the file system is implemented in each NAS device, and the NAS devices process file-level storage commands (e.g., read data from a file) received from a host computer in communication with the NAS device via a local area network (LAN).
The description above is presented as a general overview of related art in this field and should not be construed as an admission that any of the information it contains constitutes prior art against the present patent application.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.